Studies will be continued on the mechanism of action of coenzyme A transferase with particular reference to the role of substrate specificity in providing the driving force for catalysis and the examination of model reactions. Work with model reactions will include the reaction of succinic acid thiol esters and the reactions of thiol esters with carboxylate anions. Studies on the formation of aminoquinones will be continued with the aim of elucidatigg the mechanism of the 1,4 addition. The solvent isotope effect in enzyme catalysis will be studied at short times after mixing to obtain an evaluation of the importance of conformation changes. A study of the catalysis of transamination reactions will be continued. The mechanism of thiocarbamate decomposition will be studied in the presence of general acid catalysts. Catalysis of the attack of sulfite on carbonyl compounds will be studied. Rate accelerations in micelles will be examined with special reference to high-order reactions that will show large favorable entropy contributions. Bibliographic references: M. Roseman and W.P. Jencks, Interactions of Urea and Othr Polar Compounds in Water, J. Amer. Chem. Soc. 97, 631 (1975). A.C. Satterthwait and W.P. Jencks, The Mechanism of the Aminolysis of Acetate Esters, J. Amer. Chem. Soc. 96, 7018 (1974).